This invention relates to a disk apparatus such as a floppy disk drive for carrying out data writing/reading operations upon a magnetic disk medium of a floppy disk and, in particular, to a disk holding mechanism for holding a disk such as a floppy disk in a disk apparatus.
As well known, a floppy disk drive (FDD) is a drive unit for carrying out data writing/reading (recording and reproducing) operations upon a magnetic disk medium of a floppy disk inserted therein. In order to carry out such data recording and reproducing operations, the floppy disk drive must hold and rotate the floppy disk. At this time, it is required to fixedly hold the floppy disk so that its case is not moved and to chuck the floppy disk. A mechanism for fixedly holding the floppy disk so that its case is not moved is called a disk holding mechanism while a mechanism for chucking the floppy disk is called a disk chucking mechanism.
The floppy disk has a magnetic disk medium contained within the case. In addition, the floppy disk has a disk hub formed at the center of a rear surface of the case. The disk holding mechanism includes a disk holder unit for holding the floppy disk. The disk chucking mechanism includes a disk table for magnetically attracting the disk hub.
In the floppy disk drive of the above-mentioned structure, the floppy disk drive may be subjected to external shake or shock during execution of the data writing/reading operations upon the magnetic disk medium of the floppy disk (i.e., during the operation of the floppy disk drive). In this event, the disk table of the disk chucking mechanism vibrates in the vertical direction because the disk table has a backlash or looseness with respect to a drive body of the floppy disk drive. Since the disk hub of the floppy disk is no more than magnetically attracted onto the disk table, the floppy disk itself vibrates in the vertical direction with respect to the drive body. Vibration of the| floppy disk in the vertical direction with respect to the drive body brings about unstable head touch to the magnetic disk medium of the floppy disk when it is accessed by a magnetic head. This results in occurrence of a data reading error for the magnetic disk medium.